146 



Xational Resources Planning Hoard 



leum industry as we know it today. However, the fol- 

 lowing illuslralioiis will serve to bring out many of the 

 more significant phases of the subject. 



Production 



The initial problems in oil production were primarily 

 of a specialized engineering nature. Early wells were 

 relatively shallow, but the perfection of methods for 

 drilling to greater depths was soon required. In addi- 

 tion, it became necessary to improve methods of pros- 

 pecting. Well drilling was too costly a process to war- 

 rant the selection of drilling sites with a divining rod. 

 At the present time, with the assistance of geology, 

 geophysics, and more recently geochemistrj^, prospect- 

 ing has attained a remarkably high degree of perfection. 

 Intensive research in these sciences has led to the devel- 



opment of new methods and tools which have played a 

 major role in the new discoveries that have made it 

 possible to supply our demands for crude oil, and leave 

 us today with an estimated underground reserve of some 

 19,000,000,000 barrels. Aside from aiding in the loca- 

 tion of new oil deposits, research on oil production — 

 applying principles of chemical engineering operations — 

 has also resulted in greater efficiency and economy in 

 oil recovery by such means as more efficient well spac- 

 ing, controlled flow, gas repressuring, acidification, and 

 water flooding. These improvements in the eflSciency 

 of recovering oil from the ground have in recent years 

 contributed materially toward increasing the net 

 reserves. 



Of considerable importance as a conservation measui'c 

 is the improvement in locating oil deposits. Indications 

 of this improvement are to be found in the fact that the 

 petroleum industry has been able to maintain the num- 

 ber of dry holes among completed wells at approxi- 

 mately the same percentage over a number of years, 

 in spite of the less obvious surface signs of oil as drillings 

 to greater depths become necessarj'. The percentages of 

 wells wliich found oil and gas, and which were dry over 

 a number of j-ears in the United States, are tabulated 

 below: 



Table 1. — Oil wells completed in United States between 1910 and 



19S9 



1925 1927 

 Figure 32 



1929 1931 



1933 1935 1937 1939 



Production and Reserves of Crude Oil in the 

 United States, 1925-39 



Together with improved methods of locating oil de- 

 posits have gone improvements in drilling technique. 

 These improvements permit of increasing depth of 

 wells and speed of drilling. There has been a continuous 

 trend toward greater drilling depth, the first test at the 

 10,000-foot level having been reached in 1931 with first 

 commercial production from it in 1937. The greatest 

 advance in deep drilling has occiurcd since 1927, and 

 the record-holding depths of producing wells at the end 

 of each year since 1927 are as follows: 



Depth of record-holding producing wells 



Year: Depth, fed 



1927 7,591 



1928 8,523 



1930... 8,550 



1931 8,823 



1932.. 9,710 



1935 9,836 



